Signaling system



Aug. 19, 1941.

w. H. "r. HOLDEN 2,252,766

SIGNALING SYSTEM Filed Oct; 17, 1940 4 Sheets-Sheet l lf/G/ FIG-3 5 FlagRG4 mH. ZHOLDE/V A T TOR/VEV Aug. 19, 1941.

W. H. T. HOLDEN SIGNALING SYSTEM Filed Oct. 17, 1940 4 Sheets-Sheet 2FIG. 2

lA ll/EN TOR W H. 2 HOLDEN WF-Ww A TTORAIEV w. H. r. HOLDEN 2,252,766

SIGNALING SYSTEM Aug. 19, 1941.

Filed Oct. 17; 1940 4' sheets sheet 5 INVE/V TOR M. H. 7. HOLDEN A TTORNEV g- 1 1941- w. H. r. HOLDEN 2,252,766

SIGNALING SYSTEM Filed Oct. 17, 1940 4 Sheets-Sheet 4 FIG. 4

m/vs/v TOR By W H T HOLDEN Patented Aug. 19 1941 NITED STATES PATENT omSIGNALING SYSTEM William H. 'r. Holden, Woodside N. 12., assignor to.Bell Telephone Laboratories, Incorporated, New York, N. Y., acorporation otNew York I Application October 17, 1940, Serial No.361,538

8 Claims. (Cl. 179-27) v a designation are determined by the phase ofthe signals transmitted.

Another object of the invention is to simplify and otherwise improveboth the signal transmit-- ting and receiving equipments utilized in theidentification of telephone lines. I

The foregoing objects are realized by means of a system in which asignal impulse transmitter, common to a plurality of subscribers linesin a telephone oiiice, is arranged to generate a multiplicity ofimpulses of a given polarity and of different phases. These impulses areapplied to the sleeve conductor of the line to be'identii'led phases ofthe impulses'being selected'to represent the numbers or other charactersidentifying the line. The impulses thus applied to the sleeve conductorare transmitted through the switches involved in the connection toareceiving mechanism which includes a plurality of discharge tubes havingcontrol electrodes to which the incoming impulses are applied. At thesame time impulses of opposite polarity and of various phases areapplied to other control electrodes of these discharge tubes. Theparticular tubes having impulses of like phase applied to theirelectrodes operate to register the designation of the subscriber's lineinvolved in the connection. The

extending thesubscribers lines together with a portion of the impulsereceiving mechanism which receives and records the identity of thesubscribers lines; and

Fig. 4 shows the remaining part of the impulse receiving mechanism.

The present invention is particularly useful in systems in which ticketsare prepared for the P rpose of assessing the calling subscriber for.each conversation held with other subscribers.;; Since these tickets areprepared automaticallmv 4 it is necessary to determine the number of thecalling line in order that the charge be assessed-....-;; against theproper party. However, the invention may be used in any type of systemwhere it is desirable to determine automatically the over leadspermanently connected thereto, the

registered designation may then be used to control the printing of aticket to charge for the call being made or for any other p rp se,

Other features of the invention will be described more fully in thefollowing specification;

In the drawings accompanying the specificationi- Figs. 1 to 4, whenarranged in the order shown in Fig. 5, illustrate a portion of anautomatic telephone system incorporating the features of the presentinvention.

Fig. 1 shows the subscribers lines entering the telephone omce togetherwith a portion of the .impulse sending mechanism for sending impulsesidentifying these lines:

Fig. 2 shows the remaining portion of the im pulse sending'mechanism;

Fig. 3 illustrates the automatic switches for identity of a line, trunk,or other circuit. For

example, it is often desirable to display the number of a calling partybefore the operator to whom the line has been extended, eliminating thenecessity of the operator making an oral request. or performing theusual number-checking operation.

Referring particularly to the drawings, two

subscribers lines I and 2 are shown appearing in the terminal bank ofline-finder switch F. The finder F operates to seize a subscriber's linewhen calling, and the selector switches S and S-l respond to impulsestransmitted from the subscriber's line to extend thejine over trunks tosucceeding switches, Certain of the trunks EC! oessible to switch S-l,such as the trunk 8, lead to the tandem oilice or to distant zonesrequiringthe preparation of a ticket for charging the call. To this endthe trunk l is provided with the necessary equipment 4 for preparing aticket con-v taining the calling subscriber's number, the calledsubscriber's number and the. proper charges for the call. a

Theldentity of a particular calling subscriber's line is determined bythe impulse generating and transmitting mechanism shown in Figs. 1 and2. This mechanism includes a system of transformer windings forproducing alternating currents having a multiplicity of separate phasesand a plurality ofdischarg'e tubes responsive to these alternatingcurrents for generating momentary im. pulses of the correspondingphases. The alter-- nating currents are supplied by sources 5 and I,

the voltages of which are maintained in quadrature relation. The sourceI is connected to the primary winding 1 of transformer l0, and thesource t is connected to the primary winding. 8'

of transformer 2|. Each of these transformers is provided with fortysecondary windings, each secondary winding of one transformer beingconnected in series with the corresponding winding of the othertransformer. These forty pairs of windings serve to produce voltages offorty difierent phases. The forty diiferent phases are divided into fourgroups of ten, these four groups corresponding to the ten differentvalues of the thousands, hundreds, tens and units digits of thesubscribers telephone numbers. For example, the No. 1 secondarywinding-9 of transformer I is connected in series with the No. 1 secondarywinding ll of transformer 20, the No. 2 winding l2 of transformer i0 isconnected in series with the No. 2 winding (not shown) of transformernamely tubes 2|, 22, 22, 24, 25, 2e, 21 and] 28.. For example, thecircuit including the first pair of windings 9 and Ii may be traced fromground through winding H, conductor 29, winding 9,

conductor 20, resistance 3| to one of the electrodes of tube 2| and alsoto one terminal of condenser 22, the other terminal of which isconnected through battery 33 to ground. The second pair of windings areincluded in a circuit respectively, the number of subscriber's line I iseach of the forty difleren-t voltages occurring at y forty differentperiods in the cycle.

The forty impulse generating tubes to which the supply circuits areconnected are arranged to discharge and produce impulses once duringeach positive half-cycle of the supply voltage. Accordingly, the fortytubes produce forty successive impulses per cycle, and each one of thesubscribers lines is identified by connecting its sleeve conductor to acombination of four of the impulse generating tubes, one tube in each ofthe thousands, hundreds, tens and units groups. The

subscriber's line I, for example, ha its sleeve conductor. 48permanently connected by way of the connecting rack 41 to the generatingtubes 22, 24, 28 and 28. The connection from the tube 22 extendsover'the impulse circuit 49 through resistance 50 to the sleeveconductor, the circuit from tube 2 4 extends over impulse circuit 5|through resistance 52, the circuit from tube 28 extends over impulsecircuit 53 through resistance 54, and the circuit from tube 28 extendsover impulse conductor 55 and resistance 58- to said sleeve conductor.Since the tubes 22, 24, 26

and 28 are the No. 7. No. 6, No. .8 and No. 9 tubesin the thousands,hundreds, tens and units groups.

7689. In like manner, the sleeve conductor 51' of subscriber; line 2 isconnected. permanently which extends over conductor 34 to the secondenerating tube (not shown) Similarly the next eight pairs oi windingsare included in circuits 3!, 36,- 31, ll, 39, 40, 4| and 42-, extendingto the corresponding'eight impulse generating tubes of which one tube,tube 22, is shown in the drawings. These first ten supply circuits 42and the corresponding ten tubes constitute the thousands group and serveto transmit the impulses representing the ten diflerent values that thethousands digit.

may have.

The next ten pairs of secondary transformer windings are included in theten supply" circuits 44 which are connected to ten diflerent impulsethrough resistances 58, 59, 60 and BI to the im-'- pulse genera-tingtubes 2!, 23, 25 and 21, the number oi'line 2 being 1132. 'Likewise,each of the remaining subscriber's lines in the omce is connected to adiflerent combination of impulse generating tubes for identifying itsnumber. The

purpose of the resistances between the impulse generators and the sleeveconductor is to prevent the impulses of one generator from appearing onthe impulse leads of other generators.

l The line identifying equipment, which is asso- I ciated with theseized outgoing trimk 3, includes a series of forty discharge tubes62,63, 64, 65

tubes,.including tubes 22 and 24. These ten supply circuits and tubesconstitute the hundreds group and serve to transmit the impulsesidenti-' tying the diflerent values of the hundreds digit.

In like manner-the tens group is comprised of ten supply circuits 4! andten impulse. tubes, including tubes 25 and 26; and the units groupcomprises ten supply circuits and ten generating tubes, including thetubes 21 and 28.

Since the voltages of the sources 5 and 6 are in ofthc' voltagesproduced in the forty consecutive supply circuits-42, 44, 45 and 48, by.graduating the number of turns and the poling of the windings in thesuccessive secondary windings of the 68, 61, 88, 69, etc. Theseidentifying tubes respond to the impulsestransmitted from the sendingequipment associated with the calling subscriber's line and also respondto impulses of varying phases, produced locally in the receiving,equipment. These local impulses are produced by a series of fortyimpulse generating tubes 10, II, 12, 13, I4, 15, l6, 11, etc. The al-'ternating currents of diflerent phases for ener- .gizing the tubes I0,1|, 12, etc., are supplied by the four groups of supply circuits I8, 19,so and quadrature, itis possible to graduate the phases a transformersII and 2c. The voltagein the supply circuit ll, for instance, is theresult of the.

voltages in'windings I and il, the'phasesofwhich are at right angles toeach other. Therefore, the

I .phase oftheresultantvoitagema'ybeilxedatany desired time in thecycleby properly selecting the relative number of turns on windings 2 and II.Similarly the relatively number-oi turns and pomy on the remaining pairsor windings are lclected in such a manner that the phases of thevoltages in the supply circuits are spaced at-sub- 'stantially uniformintervals. In other words, the

voltagein each of the forty consecutive supply circuits 24, I4, 2!,28,21, etc., rises to its maximum value once per cycle or thesourceiraifd 0,

Ii. The-forty supply circuits in the four groups are connected,respectively, to the forty pairs of secondary windings on thetransformers SI and Hill. The primary windings 82' and 83 of thesetransformers are connected to-voltage sources 84 and BI which are inquadrature relation and which are in phase, respectively, with sources Iand 6 supplying the'transformers l0 and 20. .If desirable, the primarywindings I and 82 may be supplied from the same source and primarywindings l and 82 from a second source which is in quadrature to thefirst source. The secondary'windings of the transformer I areconnectedrespectively in series with the corresponding secondary winding of thetransformer. ",the

same as the windings of transformers II and 20.

Thus the ten supply circuits 18, the ten impulse generating tubes towhich these are connected, including tubes II and". and the tenindicating tubes associated with the respective generating tubes,including the tubes 62 and 83,.

constitutethe thousands group and serve to inas the trunk 3, requiringits services.

,tion to other leads, the connector 88 extends the the ten indicatingtubes, including tubes 84 and 88, constitute the hundreds group foridentifying 3 I82 of phase No.' 1. Hence the anode supply voltage willbe at substantially its maximum the value of the hundreds digit of thenumber. a

In like manner the tens and units groups include the supply groups 88and II, respectively, the associated groups of impulse generating-tubesand the associated groups of indicating tubes, the latter including thetubes 88 and 81 and the tubes 88 and 08. 4

Since the receiving and indicating equipment is common to a plurality oftrunks, a connecting device 88 is provided for connecting the indicatmgmechanism with any particular trunk, such sleeve conductor of theconnection through to the impulse receiving conductor 81 which deliversthe incoming impulses to the forty indicating tubes 82,88, 88. etc. Ifdesirable, the incoming impulses may be amplified to increase theirenergy by a suitable amplifier 88. After amplification, these incomingimpulses are applied over the common conductor 88 and through resistanceelements 8|, 82, 88, etc., to one of the control electrodes of each ofthe indicating tubes, such as the electrode 88 of tube 82. The othercontrol electrode of each indicating tube, such as the ply circuits I8,18, 88 and M are in, phase with the correspondingvoltages produced inthe forty supply circuits 8!, ll, 88. and 48 at the sending end, theforty successive impulses applied to the electrodes of the indicatingtubes 82, 88, 84, etc., are in phase respectively with the fortyimpulses produced in the impulse circuits'oi generating tubes 2I, 22,23, etc., for each positive half-cycle oi the alternating voltage. Itfollows, therefore, that ii any particular combination of fourgenerating tubes 2i, 22, 28, etc., are connected to In addivalue at theinstant ionization occurs across the control gap 84-88, and the relay 81obtains a maximum current flow at each ionization of the tube, that is,at each positive half-cycle oi the j I supply voltage. The relay 8! isdesigned to operate after a succession of impulses have been receivedand to maintain its operation between successive ionizations oi thetube. Each [of the indicating relays may be operated by a separatetransformer, the transformers being connected to therespective supplycircuits I02, I08, I04, I05, I00, etc. However, it is sufiicient toconnect a group of live successive relays to the secondary winding of asingle transformer 88 as illustrated in the drawing. In other words, thephases of a series of. five consecutive supply circuits are suflicientlyclose to insure the operation of all five of the indicating relays. Withthis arrangement it is only necessary to provide a transformer for eachfive relays. Transformer 88 serves the first five relays, includingrelay 8|.- Transformer I0I'serves the next five relays, including relay98, and derives its energizing current from the supplycircuit I08.-Similarly, other transformers I08, IIO, III, I80, I and- 2 supply thesucceeding groups of indicating relaysi To further describe the detailedoperation of the indicating system disclosed herein, it will be assumedthat the subscriber oi line 2 wishes to. .make .a call requiring thepreparation of a ticket Thereupon the subscrlber'manipulates his dial tooperate selector switches S and S-I to extend 8 and thence over the tipand ring conductors III to a distant oflicefi; As soon as the trunk 8 isseized,- the controlling equipment 4 causes the the sleeve conductor ofthe line and this sleeve conductor is extended through to the impulsereceiving-conductor 88 associated with the forty indicating tubes 82,88, 84, etc., the correspondingfour indicating tubes will have impulsesapplied simultaneously to their control electrodes. Since, as will bedescribed hereinaiter, the impulses producedby the tubes2l, 22, 23,etc.,-are positive in polarity-and the impulses produced by generatingtubes I0, II, 12, etc., are negative in polarity, the simultaneousapplication of a positive and a negative impulse to the controlelectrodes of an indicating tube produces suiilcient voltage acrossthese electrodes to ionize the tube. Hence the four indicating tubeswhich correspond to the tour generating tubes connected to the sleeveconductor of the line are ionized and cause the operation of theirassociated indicating relays .81, 88, IN, etc., to identify the digitalchar acters of the subscriber's line.

Itwill-be noted that the anode circuit of the tube 82 is connected tothe secondary winding ofthetransformer. 88 and that the primarywindingof this transformer is energized by the althe charging at,condenser 82.

pletion of the impulse transmitting circuit the voltage of phase No. 1in supply circuit causes Upon reaching the breakdown voltage of tube 2|the charge on condenser 82 causes the tube to ionize, and our- (iii .conductor 3 is made positive with respect to ground. This positivepotential impulse is transmitted through the condenser i52, resistance58,

sleeve conductor 51 thence through .the switches S and S--I to thesleeve conductor Ill of trunk 3 throughthe connector 88, conductor 81,am-

, plifier 88, conductor 88 thence in parallel through resistances 8| 82,98, etc., to the control electrodes oi the respective tubes 82, 88, 88,etc.-

At the same timethe alternating current or phase No.- 1 flows oversupply circuit I02 through resistance H8, condenser Il8, rcsistance Ill,battery I I8 to ground. The condenser I I0 is charged in this circuituntil it reaches the ionizing voltage 2I at the sending end. When thisvoltage is reached, the condenser II6 discharges across the gap of tubeIII and current flows through the resistance ill in such a directionthat the pulse conductor I I9 is made negative with respect to ground.This negative potential on conductor H9 is transmitted through condenserI23 and resistance I2I and is applied to the control electrode 96 of thetube62. Thus, the control electrodes 94 and 96 of tube 62 are madepositive and negative,- respectively,'at the same instant in response tothe potential impulses, one of which is transmitted from the tube 2| andthe other from the tube I3 during the positive half-cycle of thealternating current of phase No. 1 The control gap of tube 62 ionizes,and current flows from the positive pole of battery I22, secondarywinding of transformer 33, indicating relay 91, anode 96, cathode I23toground; Hence the voltages of the battery I22 andtransformer 98combine to cause the flow of current in the anode circuit through thewinding of relay 9! in phase with the ionization of the control gap ofthe tube. For each successive impulse delivered by the tube 2I and thecorresponding impulse deliveredby tube III, the indicating tube 62ionizes and an impulse of current flows through the winding of relay 91.Relay 31 operates after a number of these impulses have been deliveredand retains its armature until the impulses cease.

Later in the cycle of sources 6 and 6 the voltageinsupply circuit I24rises to its maximum ampli-' tude in its positive half-cycle and currentflows through the resistance I25, condenser I26, battery I21 to ground.when thecondenser I26 reaches the required voltage, it dischargesthrough the tube 23'and resistance I23, and a positive impulse istransmitted through condenser or No. 2 in the units group,

I53, resistance 59 and thence over the sleeve connection to the'commonconductor 39. The phase of this impulse is No. 11 in the series of'fortyphases or No. 1 in-the hundreds group 44. This impulse appearing onconductor 89 is also applied to the control electrodes of all forty oithe indi-' cating tubes. At the same instant voltage .of phase No. 11appears in the supply circuit I29, condenser I36 is charged, and thetube I2 is ionized to produce a negative impulse which is applied to thecontrol electrode I-3I of tube 64.

Since the control electrode I32 of this tube isat positive potential atthis instant, the tube ionizes, and current flows from battery I33 andtransformer winding I03 through the indicating relay IOI and theanode-cathode gap of the tube to ground. After a succession of impulsesof this phase, relay IOI operates and remains operated as long as theimpulses continue.

In like manner for each cycle of sources 6 and 6 the tube 26 produces apositive impulse of phase No. 23, or No. 3 in the tens group, 21produces a positive impulse of phase No. 32, and these impulses aretransmitted over the sleeve conductor and applied. to the electrodes ofthe indicating tubes 62, 63. 64. Also in like manner tube 14 produces anegative impulse of phase No. 23 and tube .16 produces impulses of phaseNo. 32, andthese impulses are applied to indicating tubes 66 and '68,resulting in the operation of indicating relays I34 and I36. Thus thenumber of the calling line, 1132, is

- identified by the operation of relays 31. I 0|, I34

and tube in the group of forty relays operates because the impulsesapplied to the associated indicating tubes are not in phase with eachother. Relays 91, I III, I34 and I35 apply ground potential overconductors I36, I31, I38 and I39 to the control mechanism 4 associatedwith the trunk 3. These ground potentials may serve to operate a printerto print the number of the line 2 on a message ticket. After theinformation concerning the calling line as well as the informationconcerning the called line has been recorded in the control mechanism 4,the identifying .mechanism may be disconnected from the trunk byreleasing the connecting device 66. I

Should the subscriber of line I extend a connection requiring thepreparation of a ticket the number of this line is identified in themanner already described, except that the positive impulses foridentifying the number of line I are transmitted by the generating tubes22, 24, 26 and 2,8, and the phases of these impulses correspond to thenumber 7689.

Although the invention has been illustrated as applied to an automaticsystem in which the numbers of subscribers lines are identified for thepurpose of preparing message tickets, it will be understood that it mayalso be used for identifying the numbers of lines at operatorspositions.

means for generating a multiplicity of signal im-,

pulses of different phases, connecting means betweensaid generatingmeans and said lines for applying to each line a, plurality of saidsignal impulses in a combination of phases representing the linedesignation, a circuit for transmit. ting the impulses pertaining to aparticular one of said lines, and means for receiving and utilizing thetransmitted impulses to identify said particular line. V

2. In a signaling system, a plurality of .lines each of which hasan'identifying designation, means for generating a multiplicity ofsignal impulses of different phases, connecting means between saidgenerating means and said lines for applying to each line a plurality ofsaid signal impulses in a combination .of phases representing the linedesignation, a connection including a particular one of said lines, saidestablished connection serving to transmit the impulses applied to saidparticular line. and means associated with the established connectionselectively operated in accordanbe with the phases identifying saidparticular line.

3- In a signaling'system, a plurality of lines each of which has anidentifying-designation, means for generating a multiplicity of signalimpulses of diflerent phases, a plurality of leads permanentlyconnecting said generatingmeans to said lines for applying to each linea group .combinationof phases of signal impulses in a representing theline designation, a circuit for transmitting the impulses pertaining toa particular one of said lines. and means for receiving and utilizingthe transmitted impulses to identify said particular line.

4. In a signaling system, a line having a control conductor, means forgenerating a plurality of signal impulses of difi'erent phases,connecting leads permanently connected. between said generating meansand the control conductor of to said conductor a group of said impulsesthe phase combination of means for establishing of the transmittedimpulses for which represents the designation of said line,

means for establishing a connection from said line, said establishedconnection serving to transmit the impulses applied to said controlconductor, and means for receiving and utilizing the transmittedimpulses for determining the designation of said line.

5. In a signaling system, a line having a control conductor, means forgenerating a plurality of signal impulses oi different Phases,connecting leads permanently connected between said generating means andthecontrol conductor of means for establishing a connection from saidsaid line for transmitting to said conductor a group of said impulsesthe phase combination of which represents the designation of said line,means for establishing a connection from said line, said establishedconnection serving to'trans-' mit the impulses applied to said-controlconductor, and a receiving mechanism comprising a plurality of,discharge tubes selectively responsive to said transmitted impulses inaccordance with'the phases thereof. 7

' 6. In a signaling system, a line having a control conductor, means forgenerating a plurality oi. signal impulses or diflerent phases,connecting leads permanently connected between said generating means andthe control conductor of said line for transmitting to said conductors;

group oi'said impulses the phase combination of which represents thedesignation of said line, means for establishing a connection from saidline, said established connection serving to transmit the impulsesapplied to said control conductor, a receiving mechanism comprising aplurality of discharge tubes each having control electrodes, a secondimpulse generating means for generating impulses of diflerent phases andapplying them to the control electrodes 01' said tubes, and means forapplying to the control elecline, said established connection serving toits mit the impulses applied to said central cons ductor, and means forreceiving and l the transmitted impulses for determining designation ofsaid line. 8. In a signaling system, a line having a cone trolconductor, a source of alternating warrant,

' means responsive to said source for generating a plurality ofsuccessive signal impulses during each cycle of said current, means forapplying to said control conductor a group of the impulses generated ineach cycle, said group being selected to characterize 'thedesignation ofsaid line, means for establishing a connection from said line, saidestablished connection serving to transmit the impulses applied to saidcontrol conductor, a plurality of discharge tubes, meangresponsive tosaid source of alternating current for generating successive signalimpulses during each cycle andv for applying saidimpulses to the controlelectrodes oi said tubes, and means for applying the impulsestransmitted over said control conductor to the control electrodes ofsaid tubes to selectively operate said tubes in accordance with the desination of said line..

WILLIAM I1: '1'. 30mm.

